An image-forming machine having plural image-forming paper feeders such as paper feed trays, paper feed tables, and others is known. As shown in JP-A No. 1994-24606, when such an image-forming machine has plural paper trays containing an identical size of paper, the machine can be configured so as to select a paper tray of the lowest jamming rate.
In an image-forming machine, an image-forming speed at an image-forming section has to match the feed speed of paper fed from a paper feeder to the image-forming section. Here, the feed speed of paper fed from a paper feeder to the image-forming section: depends on the shape of a paper traveling route formed between the paper feeder and the image-forming section; can be increased when the traveling route is straight; and, instead, has to be reduced by as much as a curved portion of a large curvature when the portion exists.
In the case of an image-forming machine having a relatively slow image-forming speed, it is not necessary to care about the shape of a traveling route connecting a paper feeder to an image-forming section or to take a paper feed speed as the criterion for selecting one from among plural paper feeders. Then for example, a method for selecting a paper feeder on the basis of a jamming rate like the invention described in JP-A No. 1994-24606, a method for detecting the amounts of remaining paper and selecting a paper feeder having a larger amount of remaining paper, or a method for selecting a paper feeder equally so as to average the wear of consumable supplies in the paper feeders can be used.
In the case of such an image-forming machine as a stencil printing machine that allows high speed printing for example, however, a paper feeder is required to have a high paper feed speed that can conform to the printing speed in order to exhibit a high speed printing performance and thus the paper feed speed of each paper feeder determined by the position of the paper feeder and the shape of the traveling route cannot be ignored.
In view of the above situation, an object of the present invention is, in an image-forming machine equipped with plural paper feeders that feed paper to an image-forming section at different paper feed speeds in proportion to the difference of the shapes of paper traveling routes and the like, to control the image-forming machine so as to be able to select a paper feeder suitable for conditions, such as the improvement of a printing speed, required by users.